Microbial communities within saltmarsh sediments: Composition, abundance and pollution constraints

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Machado, A (Author) Other; Magalhaes, C (Author) Other; Mucha, AP (Author) Other; Marisa M R Almeida (Author) FCUP; Adriano Bordalo (Author) ICBAS

Journal

Title: Estuarine, Coastal and Shelf Science

Vol. 99

Pages: 145-152

ISSN: 0272-7714

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 11 Citations

Scopus - 12 Citations

Other information

Authenticus ID: P-002-CCC

DOI: 10.1016/j.ecss.2011.12.028

Abstract (EN): The influence of the saltmarsh plant Halimione portucaloides and the level of sediment metal contamination on the distribution of microbial communities were investigated in two Portuguese estuarine systems with different degrees of metal contamination: the Cavado (41.5 N; 8.7 W) and Sado estuaries. In the Sado, two saltmarshes were studied: Lisnave (38.4 N; 8.7 W) and Comporta (38.4 N; 8.8 W). A PCR rDNA-DGGE approach and direct microscopic counts of DAPI-stained cells were applied to study the biodiversity and abundance of prokaryotic communities. Sediment characteristics and metal concentrations (Cd, Cr, Cu, Fe, Pb, Mn, Ni and Zn) were also evaluated to identify possible environmental pollution constraints on spatial and temporal microbial dynamics. Redundancy analysis (RDA) revealed that the Lisnave saltmarsh microbial community was usually associated with a higher degree of metal contamination, especially the metal Pb. In clear contrast, the Cavado estuary microbial assemblage composition was associated with low metal concentrations but higher organic matter content. The Comporta saltmarsh bacterial community clustered in a separate branch, and was associated with higher levels of different metals, such as Ni, Cr and Zn. Additionally, the microbial community structure of the Lisnave and Cavado showed a seasonal pattern. Moreover, microbial abundance correlated negatively with metal concentrations, being higher at the Cavado estuarine site and with general higher counts in the rhizosediment. These findings suggest that increased metal concentrations negatively affect the abundance of prokaryotic cells and that saltmarsh plants may have a pivotal role in shaping the microbial community structure.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8